<template>
  <!-- 输入框 -->
  <header class="header">
    <h1>小黑记事本</h1>
    <input @keyup.enter="add" v-model="todoName" placeholder="请输入任务" class="new-todo" />
    <button class="add" @click="add">添加任务</button>
  </header>
</template>

<script>
export default {
  data() {
    return {
      todoName: '',
    }
  },
  methods: {
    //添加任务
    add() {
      //子传父
      if (this.todoName.trim() === '') {
        alert('任务名称不能为空')
        return
      }
      this.$emit("add", this.todoName)
    }
  },
}
</script>

<style>
</style>